[Satellite Release] v0.21.0

[deploystack-automation]

Satellite Release v0.21.0

This PR prepares a new satellite release.

When merged, this will:

1. Create a release tag
2. Build and publish a multi-architecture Docker image to Docker Hub

The Docker image will be available at:

• deploystack/satellite:latest
• deploystack/satellite:v0.21.0

Supported Architectures

• linux/amd64 (Intel/AMD)
• linux/arm64 (Apple Silicon, AWS Graviton)

Release notes:

• feat(all): add OAuth requirement field, hierarchical router improvements, and tool filtering (231b175e)
• fix(all): use WAF-friendly User-Agent headers for HTTP MCP server requests (2c9cae01)
• feat(all): add reconnect button for offline HTTP/SSE MCP servers (92ff5093)

[deploystack-automation]

Release Branch Cleanup ✅

Branch satellite-release has been automatically deleted after PR was merged.